The priority in fire fighting is to Save life, then protect property. Essentially, ensure the driver is out and okay, then worry about the car he was driving.
Fires in vehicles are complex fires to deal with. There are a lot of different substances which burn at different temperatures and produce sometimes toxic smoke. The aim when dealing with a fire is to get the driver out, and the incident under control, if not extinguished within 30 seconds. This is easily achievable if the correct techniques are used when it comes to using fire extinguishers.
Whats burns on a car
The majority of cars will run on unleaded fuel. However, diesel and in some cases ethanol is used. Ethanol is a very pure fuel thats sometimes found in older cars. Enthanol burns with a slow, clear flame and is difficult to see. Like petrol, it can cause burns if it contaminates the skin.
Brakes are particularly dangerous as disks can shatter if suddenly cooled by water or foam. A brake fire is most likely to occur if the car is involved in an accident or stops on circuit. The brake fluid when it ignites can ignite the pads or associated bodywork.
- On engine/turbo fires
These are often caused by turbos or other engine malfunction. Be very aware of the dangers of fires lurking under bodywork (bonnets, wings etc) where you cant often see. Be careful of thermal shock, where using AFFF on hot engines can cause it to fracture or worse.
Plastics, GRP and trim all give off toxic smoke when burnt. Care should be taken to approach with the wind behind you so to limit the effects of the smoke. Avoid skin contamination as some plastics give off a highly corrosive acid which will do damage to the skin.
Fire Extinguishers are a marshals first line of defence in the event of a vehicle fire. Fires can often be caused by mechanical failure or accident damage. It is vital that marshals understand the operation of fire extinguishers (or bottles) their effects and how they work to extinguish the fire.
Principles of Extinction
Types of Fire Extinguishers
Water fire extinguishers are filled with fresh water and work by cooling the fire. These are suitable for freely burning materials such as Wood, Paper and textiles only and are not found on post.
- Aqueous Film Forming Foam (AFFF)
AFFF Fire extinguishers are filled with 90% water, 10% AFFF. The AFFF is a chemical derived substance that works to smother the fire, removing the oxygen from flammable liquid fires. The water in the foam mix also helps to cool the fire, preventing re-ignition. These are cream coloured and are commonly found on post, in pitlanes and paddock areas.
- Dry Powder
Dry Powder extinguishers contain a mixture of chemicals which work to smother the fire, removing the oxygen. A Dry Powder fire extinguisher has no cooling properties and must always be used in conjunction with AFFF extinguishers which provide the cooling effect. Dry Powder extinguishers can be used on freely burning materials and flammable liquids. They are coloured blue and are found on marshals posts in conjunction with AFFF Fire Extinguishers.
- Carbon Dioxide (CO2)
CO2 Extinguishers work by replacing the oxygen within the seat of the fire with CO2 which is non sustainable to the fire, so it will go out. Carbon Dioxide Extinguishers will extinguish small scale fires involving flammable liquids, however are much better at extinguishing fires involving HV or electrical appliances and therefore are often found within Race Control and not on post.
BCF/BTM Halons are o-zone depleting gasses that were used in Fire Extinguishers until the late 1990's. They are now not to be used and are not found on post or within circuits.